1. Field of the Invention
The present invention relates to a connector, comprising connection terminals and a connector housing having terminal receiving chambers. More particularly, the present invention relates to a connector in which a lance displacement detection pin of a connector inspecting instrument is inserted into the terminal receiving chamber so as to detect a half-insertion condition of the connection terminal.
The present application is based on Japanese Patent Application No. Hei. 11-337355, which is incorporated herein by reference.
2. Description of the Related Art
A connector, used for connecting vehicle""s wire harnesses or the like together, comprises electrically-conductive connection terminals of a known construction, and a connector housing of a synthetic resin for receiving the connection terminals.
Terminal receiving chambers for respectively receiving the connection terminals are formed in the connector housing. The terminal receiving chambers extend through the connector housing from a front end surface thereof to a rear end surface thereof, and terminal insertion ports are formed in the rear end surface of the connector housing, and connection ports for respectively receiving mating connection terminals are formed in the front end surface of the connector housing.
A lance for retaining the connection terminal, received in the terminal receiving chamber, and an elastic displacement-allowing space for the lance are formed within each terminal receiving chamber. The lance has a tongue-like distal end portion, and a retaining projection for engagement with the connection terminal is formed on the distal end portion of the lance.
A lance displacement detection pin of a connector inspecting instrument is inserted into the elastic displacement-allowing space through the insertion port, formed in the front end surface, so as to detect a half-insertion condition of the connection terminal.
More specifically, in a half-insertion condition of the connection terminal, the lance is kept elastically deformed by the connection terminal (The lance is kept stranded on the connection terminal, with the retaining projection held in contact therewith). The distal end (the distal end portion and the retaining projection) of the lance is displaced with respect to the proper retaining position, and is disposed in the elastic displacement-allowing space. In this condition, when the lance displacement detection pin is inserted into the elastic displacement-allowing space, this pin abuts against the distal end portion of the lance, thereby detecting the half-insertion condition of the connection terminal.
In the above related example, the connector housing need to be so formed that the distal end of the lance can be displaced as much as possible so that the half-insertion condition of the connection terminal can be positively detected.
Therefore, it may be proposed to increase the height of projecting of the retaining projection on the lance. However, a terminal inserting force, required for inserting the connection terminal during an assembling operation, becomes too large, thus affecting the operation efficiency, and therefore this proposal has not served as an effective countermeasure.
With the above problem in view, it is an object of the present invention to provide a connector in which a distal end portion of a lance can be displaced as much as possible without increasing a terminal inserting force.
To achieve the above object, according to the first aspect of the present invention, there is provided a connector which comprises a connector housing including a terminal receiving chamber into which a connection terminal is insertable, the terminal receiving chamber having a displacement-allowing space, a lance formed in the terminal receiving chamber, the lance having a distal end portion which extends in an inserting direction of the connection terminal, wherein the connection terminal is inserted into the terminal receiving chamber while pushing the lance to enter the distal end portion thereof into the displacement-allowing space, and is retained by the lance in a complete insertion state thereof to be prevented from moving in a withdrawing direction opposite to the inserting direction, and a groove extending in the inserting direction of the connection terminal, the groove being formed in a wall of the terminal receiving chamber which is opposed to the connection terminal, and has the displacement-allowing space formed therein, wherein the distal end portion of the lance enters the groove in accordance with insertion of the connection terminal, and wherein length of the distal end portion of the lance is determined in accordance with a depth of the groove.
Preferably, the lance may be formed in a cantilever manner with respect to the connector housing to be elastically deformable.
In the present invention, the groove, into which the distal end portion of the lance can be inserted, is formed in the wall of the terminal receiving chamber toward which the distal end portion of the elastically-deformed lance moves, that is, the wall to which the received connection terminal is opposed through the displacement allowing space disposed therebetween. The length of the distal end portion of the lance is determined in accordance with a depth of the groove.
With this construction, when the connection terminal is received in the terminal receiving chamber in the connector housing, so that the lance is elastically deformed by the connection terminal, the amount of displacement of the distal end portion of the lance is larger as compared with the related construction. In a half-insertion condition of the connection terminal, also, the amount of displacement of the distal end portion of the lance is larger.
A lance displacement detection pin of a connector inspecting instrument for detecting a half-insertion condition of the connection terminal can be inserted into the groove, and therefore a half-insertion condition of the connection terminal can be positively detected.
The lance may have a retaining projection which engages the connection terminal to be retained in the terminal receiving chamber. In this case, the distal end portion of the lance is projected from the retaining projection so as to enter the groove in accordance with insertion of the connection terminal. However, it should be noted that the connector of the present invention is not so designed that the projecting height of the retaining projection on the lance is greater. Accordingly, a terminal inserting force, required for inserting the connection terminal during the assembling operation, is not large.
With respect to the groove, the wall of the terminal receiving chamber may be formed stepwise to thereby form the groove therein. With respect to the wall in which the groove is formed, it may be one of walls of the terminal receiving chamber which define the displacement-allowing space. With respect to the location of the displacement-allowing space, it may be disposed forwardly of a proximal end portion of the lance in the inserting direction of the connection terminal.
According to the second aspect of the present invention, it is preferable that the groove extends from an insertion port for the lance displacement detection pin to a vicinity of a portion of the wall with which the proximal end portion of the lance is integrally formed. In this case, the elastic deformation of the lance is not influenced by the groove. In other words, the force of retaining of the connection terminal by the lance is not lowered by the groove. Similar to the first aspect of the present invention, a terminal inserting force, required for inserting the connection terminal during the assembling operation, is not large.
According to the third aspect of the present invention, it is preferable that a width of the groove in a direction perpendicular to the inserting direction of the connection terminal is smaller than a width of the displacement-allowing space in the same direction as the width of the groove. In this case, the structure is not complicated. And besides, the terminal inserting force, required for inserting the connection terminal during the assembling operation, as well as the force of retaining of the connection terminal by the lance, is not affected.